Composite tag to geocode lat and lon to city, state, country (config file)

[wywh]

12.78 with the new Geolocation feature

Great! Which database does it use?

- Matti

[FrankB]

I've just released version 12.78 with the new Geolocation feature.  Have fun with it!

- Phil

I'm playing and having fun. Thanks.
I do have some questions, but since they're more ExifToolGui I will post it there.

[Phil Harvey]

Hi Matti,

Great! Which database does it use?

The >1000-population city database from geonames.org that FrankB mentioned, but I have reformatted the database to reduce the file size.

I've already added another feature to allow user-defined cities to be added, and am using that myself to geolocate pictures from my last trip because we stayed in some very small towns that aren't in the database.  The user-defined city feature will appear in 12.79.  I may also provide the geonames.org >500-population database as an optional download.

- Phil

Edit: I've uploaded the  >500-population database in case someone wants to use it.  Just unzip it and either replace lib/Image/ExifTool/Geolocation.dat with this new file, or set $Image::ExifTool::Geolocation::databaseFile in your ExifTool config file to the path name of the database file.

[FrankB]

I have posted something in the ExifToolGui forum. Because I think it applies mostly to GUI.
https://exiftool.org/forum/index.php?topic=15799.0

[wywh]

The >1000-population city database from geonames.org that FrankB mentioned, but I have reformatted the database to reduce the file size.

Thanks for the info. I compared city center GPS coordinates that 'exiftool -api geolocation=44.03411,-72.06292' gives (44.033,-72.065) and what the cities1000.txt gives (44.03451,-72.06398) and wondered if some another database was used because they are slightly different.

I wonder who has determined all those city centers because many seem to be just casually thrown there 

- Matti

[Phil Harvey]

Hi Matti,

Yes, I packed the coordinates into 2-byte integers, so there was some rounding.

- Phil

[StarGeek]

Is there a definition to the Geolocation.dat format so that it could be possible to make our own from some other database?

Also, for the Windows executable, maybe check the executable's directory for a replacement Geolocation.dat?

[Phil Harvey]

The format specification is in the comments of Geolocation.pm, and I describe how to use an alternate database at the bottom of the Geolocation instructions here.  However the next release will allow user-defined cities and give an example of how to import a CSV-format database.

- Phil

[Phil Harvey]

It would have been cool if I could use this feature to automatically set the default time zone when geotagging from a GPX file, but unfortunately it is a chicken-and-egg problem because the location needs to be known to determine the time zone, and the time zone needs to be known to look up the location in the GPX track.    Darn.

However, I will enhance the -geotag feature in ExifTool 12.79 to allow the Geolocation tags to be set at the same time as the GPS tags.

- Phil